Flywheel is hard to turn

Hello all,

I have a 2004 Polaris Sportsman 500 HO. The four wheeler was running great, however, it died yesterday while driving on the trail. When I went to restart, the engine struggled to turn over (via elect start). I tried the pull start, however, it was very hard to pull.

I towed the four wheeler back to my garage to investigate further. I first jacked up the rear to lift the back tires of the ground. I tried to start again, no change. Thus, I assume its not a clutch issue. I then removed the spark plug and tried again. No change. The engine still labored to turn over.

I have inspected the flywheel and see no visible damage. Thus, I am stuck. Has anyone else experienced this issue? Any other troubleshooting guidance you can provide? Thank you in advance.

Andrew